Aboard the Stellosphere, Miles and M.E.R.C. begin the day racing against the clock in an attempt to make a new speed record. With Miles riding M.E.R.C., the two friends race through the hallways, dodge obstetrical through the mess hall and complete the course with a new speed record of forty-five seconds. Pleased with their fastest time, Miles decides that it is time to compete against some competition. They go and see Miles' Dad and ask him if he would like to challenge them in a race around the ship. Unfortunately, as much as he wants too, Leo turns them down on the challenges as he is far too busy building a new booster for the Star Jetter. Miles and M.E.R.C. then try asking Mom, but she turns them down as well as she too is busy mapping a galactic highway route for the Tomorrowland Transit Authority. After Phoebe suggests on asking Loretta, Miles and M.E.R.C. go and ask but she too is busy cataloguing every alien culture in the universe and most of all is not really into racing. Just then, Stella informs the Callistos of an incoming call from the Tomorrowland Transit Authority. With the family all gathered on the bridge, Admirals Watson and Crick make contact and brief the Callistos on their new assignment: intercept an out of control ice cream shuttle and save the pilot known as Lucky Sinclair before it crashes into Jupiter's fiery moon, Io. With the mission received, the Callistos board the Star Jetter and blast off to Io

The Callistos soon arrive in time to make contact with Lucky who is locked in the shuttle's freezer, shivering. Suddenly the Callistos find themselves in a shower of space junk. Leo pulls out all the moves he has behind the controls, dodging all debris while Loretta starts getting a little space sick. They make it out in one piece with only a strike from a drifting barbecue. Loretta has calculated that because Lucky's shuttle is still accelerating, they won't be able to reach him in time before he crashes into the moon. Miles suggests on applying a turbo boost to the Star Jetter and thanks to Leo, he manages to rig his new booster jet under the ship, allowing the Callistos to reach Lucky just in time. Io's gravity continues to pull down Lucky's shuttle down and as soon as the Callisto's get into position they deploy the space tunnel, allowing Miles and M.E.R.C. to come aboard with five minutes to restart the shuttle's systems.

Once aboard, Miles and M.E.R.C. find the shuttle in a mess and with the artificial gravity off. Assuming the systems are malfunctioning, Phoebe instructs her son turn on the override controls, which will restart the shuttle's entire systems and free Lucky from the freezer. With Lucky free, they move on with getting the shuttle's engines back on. Suddenly the two ships go out of control and the Star Jetter rips away from Lucky's shuttle as it continues to fall. With Lucky and M.E.R.C. unable to reach the reset button, Miles uses his Lazerang to hit the button, restarting the shuttle's engines just in time to blast them back into outer space. With Lucky safe and the mission over, the Callistos return to the Stellosphere, rewarded with ice cream cones.